<?php
/*--------------------------------------------------
 czip.php [qqwry.dat]
Array
(
    [beginip] => 202.102.152.3
    [endip] => 202.102.152.3
    [country] => 山东省济南市
    [area] => 联通DNS服务器
)
--------------------------------------------------*/
  
class czip {
 var $fh; //IP数据库文件句柄
 var $first; //第一条索引
 var $last; //最后一条索引
 var $total; //索引总数
  
 //构造函数
 function __construct() {
  $this->fh = fopen('qqwry.dat', 'rb'); //qqwry.dat文件
  $this->first = $this->getLong4();
  $this->last = $this->getLong4();
  $this->total = ($this->last - $this->first) / 7; //每条索引7字节
 }
  
 //检查IP合法性
 function checkIp($ip) {
  $arr = explode('.',$ip);
  if(count($arr) !=4 ) {
   return false;
  } else {
   for ($i=0; $i < 4; $i++) {
    if ($arr[$i] <'0' || $arr[$i] > '255') {
     return false;
    }
   }
  }
  return true;
 }
  
 function getLong4() {
  //读取little-endian编码的4个字节转化为长整型数
  $result = unpack('Vlong', fread($this->fh, 4));
  return $result['long'];
 }
  
 function getLong3() {
  //读取little-endian编码的3个字节转化为长整型数
  $result = unpack('Vlong', fread($this->fh, 3).chr(0));
  return $result['long'];
 }
  
 //查询信息
 function getInfo($data = "") {
  $char = fread($this->fh, 1);
  while (ord($char) != 0) { //国家地区信息以0结束
   $data .= $char;
   $char = fread($this->fh, 1);
  }
  return $data;
 }
  
 //查询地区信息
 function getArea() {
  $byte = fread($this->fh, 1); //标志字节
  switch (ord($byte)) {
   case 0: $area = ''; break; //没有地区信息
   case 1: //地区被重定向
    fseek($this->fh, $this->getLong3());
    $area = $this->getInfo(); break;
   case 2: //地区被重定向
   fseek($this->fh, $this->getLong3());
   $area = $this->getInfo(); break;
   default: $area = $this->getInfo($byte);  break; //地区没有被重定向
  }
  return $area;
 }
  
 function ip2addr($ip) {
  if(!$this -> checkIp($ip)){
   return false;
  }
  
  $ip = pack('N', intval(ip2long($ip)));
  
  //二分查找
  $l = 0;
  $r = $this->total;
  
  while($l <= $r) {
   $m = floor(($l + $r) / 2); //计算中间索引
   fseek($this->fh, $this->first + $m * 7);
   $beginip = strrev(fread($this->fh, 4)); //中间索引的开始IP地址
   fseek($this->fh, $this->getLong3());
   $endip = strrev(fread($this->fh, 4)); //中间索引的结束IP地址
  
   if ($ip < $beginip) { //用户的IP小于中间索引的开始IP地址时
    $r = $m - 1;
   } else {
    if ($ip > $endip) { //用户的IP大于中间索引的结束IP地址时
     $l = $m + 1;
    } else { //用户IP在中间索引的IP范围内时
     $findip = $this->first + $m * 7;
     break;
    }
   }
  }
  
  //查询国家地区信息
  fseek($this->fh, $findip);
  $location['beginip'] = long2ip($this->getLong4()); //用户IP所在范围的开始地址
  $offset = $this->getlong3();
  fseek($this->fh, $offset);
  $location['endip'] = long2ip($this->getLong4()); //用户IP所在范围的结束地址
  $byte = fread($this->fh, 1); //标志字节
  switch (ord($byte)) {
   case 1:  //国家和区域信息都被重定向
    $countryOffset = $this->getLong3(); //重定向地址
    fseek($this->fh, $countryOffset);
    $byte = fread($this->fh, 1); //标志字节
    switch (ord($byte)) {
     case 2: //国家信息被二次重定向
      fseek($this->fh, $this->getLong3());
      $location['country'] = $this->getInfo();
      fseek($this->fh, $countryOffset + 4);
      $location['area'] = $this->getArea();
      break;
     default: //国家信息没有被二次重定向
      $location['country'] = $this->getInfo($byte);
      $location['area'] = $this->getArea();
      break;
    }
    break;
  
   case 2: //国家信息被重定向
    fseek($this->fh, $this->getLong3());
    $location['country'] = $this->getInfo();
    fseek($this->fh, $offset + 8);
    $location['area'] = $this->getArea();
    break;
  
   default: //国家信息没有被重定向
    $location['country'] = $this->getInfo($byte);
    $location['area'] = $this->getArea();
    break;
  }
  
  //gb2312 to utf-8
  foreach ($location as $k => $v) {
   $location[$k] = str_replace('CZ88.NET','',iconv('gb2312', 'utf-8', $v));
  }
  
  return $location;
 }
  
 //析构函数
 function __destruct() {
  fclose($this->fh);
 }
}
